For an Windows operating system boot drive, 4K random read speeds are the most important, followed by 4K random write speed, this is because there are a large number of small files in the Windows system. The 4K read/write speeds of the common flash drives are always slow, so these drives are not suitable for creating W2G drive.
And the read/write speeds you said is sequential write read/write speed, not 4K random read/write speed, so it can't run Windows smoothly.